I have recently upgraded our Exchange 2003 Server From Standard to Enterrprise due to the fact that we were hitting the 75gb limit and the information store would dismount.

After upgrading, that is still happening. It looks like the same registry key used for Standard can be used for Enterprise. I pasted in this article that seems to state that I can change that registry key up to 8000gb.

I wanted to verify with someone that is indeed the case.

6 comments Registry Tweak to set a 75GB Store Limit on Exchange 2003 Standard SP2
Posted Exchange Server on Thursday, October 20th, 2005.
The Exchange SP2 became available for download yesterday. Even though Exchange 2003 has been very stable for us, SP2 is already installed on the test server here and Ive been doing some reading to determine how soon well need to install it. The biggest positive Ive found yet is the increase in the mail database limit to 75GB on the Standard version of Exchange 2003. This is a much-needed increase, and the only reason were running Exchanges expensive Enterprise version is our need to accomodate huge attachements from cour clients. I also have a personal client in television-services who will be thrilled to know their four users can now store video clips in exchange, instead of constantly archiving to one big folder on the network.

The 75GB database limit isnt set automatically when SP2 is installed. After all, 75GB exceeds a lot of expectations of the Exchange server and the disk space on most older servers. Since so few admins read the documentation, they might miss this change and lock up their servers. The registry change below, originally explained by The Lazyadmin.com can be set to any value between 1 and 75, the maximum size of the Exchange database in GBs. By default Exchange 2003 SP2 pushes the default database size to about 18GB, which is the original 16GB maximum plus a 10% over-limit buffer to keep mail coming in while Exchange floods the system with alerts about the database size.

To expand the Exchange database, or set a limit between 1 & 75GB:

Open regedit and navigate to HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\SERVER_NAME\Private-STORE_GUID. To change the Public store limit, navigate to HKLM\SYSTEM\CurrentControlSet\Services\MSExchangeIS\SERVER_NAME\Public-STORE_GUID.
In the event your Exchange server has more than one private or public store the GUID of each store can be found by running ADSIEDIT.msc and navigating to:

SERVER_NAME, STORAGE_GROUP_NAME, and MAILBOX_STORE_NAME reflect the mail store to be changed. Then take note of the objectGUID:& value for that mail store.

Create a new REG_DWORD value in the registry key for the correct GUID. Name it Database Size Limit in Gb and set the value from 1 to 75.
Assuming you are newly setting the Database Size Limit in Gb value, it will be detected at the next size check. Reboot the Information Store service for immediate recognition.
By setting the Database Size Limit in Gb key the mailbox store will not exceed that value. When the mail store reaches 90% off that value, a default 10% buffer is allowed, it will begin to log event ID #9689 to notify you that the store limit has been reached. Once the mail store does reach the maximum limit the first size check, which happens every 24 hours at 5am, will not take the database offline. The second size check will dismount the store that exceeds the limit.

Both the % of the mail store used as a buffer and the time of the database size check can be changed within the same GUID registry key referenced above. To set either, create a REG_DWORD value named Database Size Buffer in Percentage or Database Size Check Start Time in Hours From Midnight. Set their values from 1 to 100 or 0 to 23 to change, respectively, the buffer % or the offset from midnight for the size check.

The Exchange 2003 Enterprise information store can also be limitted by the Database Size Limit in Gb key. The valid range of values is 1 to 8000. If the key is not set, the default value is 8000GB.

This regedit definitely works. Although I have not had to go above the 75GB limit on any of my servers, it definitely works below 75GB, so there's no reason to think that it would stop working above 75GB. Your installation of Enterprise Edition wouldn't have changed this registry key value, since it's designed to be managed manually, so that's probably why your info store is still dismounting.

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yostnetAuthor Commented: 2008-06-19

I changed the value in the registry to the max mentioned in the article, 8000. I am assuming that I would need to dismount and remount for it to take effect